1. Field of the Invention
The present invention relates to rotating vehicle seats and in particular, to rotating vehicle seats that can assist a passenger, such as an elderly person or a handicapped person, when entering or exiting a vehicle.
2. Description of the Related Art
Various improvements have been made over the years for such a rotating vehicle seat. In many cases, the passenger entry/exit assistance in such a rotating vehicle seat is performed by combining two movements, i.e., a horizontally rotating movement and a longitudinal sliding movement. In such a rotating vehicle seat with rotating and sliding mechanisms, when the rotating and sliding seat movements are performed by an operator or helper, the operator""s load can become especially heavy, in particular, when a heavy person is sitting on the seat.
In order to reduce the operator""s load, for example, Japanese Laid-open Utility Model Publication (Kokai) No. 5-40027 disclosed a rotating vehicle seat that performs a rotating movement and a sliding movement of the seat by means of an electric motor. However, in the above known rotating vehicle seat, the construction of the driving mechanism is complicated, and more space is necessary to store the driving mechanism within the vehicle. For this reason, it is difficult to use the known rotating vehicle seat in a small-sized vehicle.
It is, therefore, an object of the present invention to overcome this problem with the known rotating vehicle seat and to teach a simple driving mechanism, which can assist in reducing space requirements for rotating vehicle seats.
According to a first representative embodiment, a seat base may be disposed on a support and can both rotate and move in a longitudinal direction with respect to the vehicle. A driving mechanism and a driving source for driving the driving mechanism are provided. The driving mechanism may rotate the seat base when the seat base is situated between first (driving) position for sitting safely while driving and a second (intermediate) position, in which the seat base is rotated by a predetermined angle between the first position and a third (vehicle entry/exit) position. The driving mechanism also may rotate the seat base while moving the support base in the longitudinal direction of the vehicle when the seat base is between the intermediate position and the vehicle entry/exit position.
In this representative embodiment, the driving mechanism may have a simple construction and a compact size; therefore, the driving mechanism may be disposed within a lower surface of a seat body. Moreover, because the seat base only rotates between the first and second positions, and rotates and moves in the longitudinal direction between the second and third positions, the space requirements for rotating the seat base can be reduced.
The driving mechanism may include a rotating mechanism and a moving mechanism. The driving force of the driving source can be transmitted to the seat base via the rotating mechanism; on the other hand, a rotational force of the seat base can be transmitted to the support base via the moving mechanism. Thus, the construction of the driving mechanism can be further simplified. The moving mechanism may include, for example, a pinion gear, an intermediate gear that is engaged with the pinion gear, and a rack that is engaged with the intermediate gear. Thus, the size of the driving mechanism can be reduced, thereby reducing the space requirements of the driving mechanism.
Rotating vehicle seats are also taught that can smoothly change from a state in which a seat base only rotates to a state in which the seat base rotates and moves.
According to another representative embodiment, a seat base may again be disposed on a support and can both rotate and move in a longitudinal direction with respect to the vehicle. A driving mechanism and a restricting mechanism are also provided. The driving mechanism can preferably simultaneously move the seat base in the longitudinal direction with respect to the vehicle body and rotate the seat base, when the seat base is between the second and third position. The restricting mechanism can preferably restrict the support base from moving in the longitudinal direction of the vehicle when the seat base is between the first and second positions.
The driving mechanism may include, for example, a pinion gear, an intermediate gear that is engaged with the pinion gear, and a rack that is engaged with the intermediate gear. In this case, when the seat base changes from only rotating to rotating and moving, the change can be performed without causing variations in the relative positional relationship between the intermediate gear and the pinion gear.
The restricting mechanism may include, for example, a guide roller that is provided in the intermediate gear, and a restricting cam that is provided on the seat base and has a cam surface engaged with the guide roller. Thus, the construction of the restricting mechanism may be simplified.
Other objects, features and advantages of the present invention will be readily understood after reading the following detailed description together with the accompanying drawings and the claims.